Patent application No.FR-88 01188 describes a device for assembling a tubular joint with a waterbox of an automotive vehicle heat exchanger with the aid of an easily-dismountable elastic linkage. The waterbox and the tubular joint are kept assembled by at least one bracket carried by the tubular joint, oriented axially and provided with a latching tooth at its axially internal end. This latching tooth, which thrusts against the axially external end of a tubular guide lug--into which the bracket is inserted--displays the form of a hook to prevent disassembly under the effect of pressure surges inherent in the operation of the cooling system associated with the vehicle engine, and, to enable the tooth to latch on to the axially external end of the tubular guide and stop lug, a large axial clearance is necessary.
In the assembly device described in patent application No.FR-88 01188, the waterbox of a heat exchanger and the tubular joint are kept assembled with the aid of two radially elastic brackets, carried by a ring housed inside the waterbox in a semi-circular groove of the waterbox, and thrusting against a box opposite this groove, the rings latching in slots made on the end of the tubular joint which is slotted over a peripheral portion lying between the slots. In this embodiment, the most delicate part of the assembly is placed inside the waterbox and there is no visual way to check that the assembly is correctly made.
In patent application No.FR 89 06976, which is also concerned with an assembly device for a heat exchanger and a tubular joint of the foregoing general type, the bracket carried by the tubular joint and axially oriented has the configuration of a leaf-spring, approximately U-shaped, of which one bracket projects from the joint in the direction of the assembly. Like the previous one, this design, which is simpler, also does not include means serving to check that the assembly is correctly made, nor to detect any accidental disassembly.
Patent application No.FR 90 04017 describes an assembly device for a heat exchanger and a tubular joint in which a locking ring is fitted with radial pins which latch into the corresponding housings provided in two nipples which nest together and which are connected to the tubular joint and the heat exchanger respectively. The ring has an extensible portion between each consecutive pair of pins, equipped with means indicating the deformed state of the ring and designed to display a correct locking of the assembly. However, like the others, this assembly has no means of guidance facilitating the placement of the tubular joint or on in the waterbox of the heat exchanger.